Surgical micro-shaving instrument with elevator tip

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No. 60/235,220, filed on Sep. 24, 2000.

BACKGROUND OF THE INVENTION

The present invention relates to a surgical cutting instrument. More particularly, it relates to a surgical micro-shaving instrument the distal tip of which is configured to assist in tissue dissection and is particularly useful for inferior turbinate reduction procedures.

Surgical resecting instruments in which an elongate inner member is rotated or oscillated within an elongate outer tubular member has become well accepted in surgical procedures where access to the surgical site is gained via a narrow portal or passage. Typically, the outer tubular member includes a distal end defining a cutting port or window, and the inner member includes a distal end with a cutting tip for engaging and resecting bodily tissue via the cutting window. Proximal ends of the inner and outer members are commonly secured to hubs that, in turn, attach to a handpiece. The handpiece can have a motor for rotating and/or oscillating the inner member relative to the outer tubular member. The cutting tip of the inner tubular member can have various configurations specific to the surgical procedure in question (e.g., resecting, cutting, shaving, abrading, etc.), with the cutting window being suitably configured to cooperate with the particular configuration of the cutting tip. Typically, the inner tubular member defines a lumen so that the loose tissue resulting from a cutting, resecting or abrading procedure can be aspirated from the target site.

The above-described surgical cutting instruments are useful for a number of surgical procedures, especially ear-nose-throat (ENT) operations. One particular ENT procedure relates to treatment of an inferior turbinate in the sinus cavity. The role of inferior turbinate pathology and the reduction of nasal airflow are well known. In short, the inferior turbinate of the sinus cavity may become enlarged or inflamed (e.g., inferior turbinate hypertrophy) for a variety of reasons. This inflammation obstructs the patient's nasal airway, causing breathing difficulties. In cases where medicinal treatment fails, a preferred surgical treatment entails resecting submucous tissue of the inferior turbinate, thereby reducing the inferior turbinate size. In this regard, available techniques for turbinate reduction include turbinectomy, submucous turbinectomy, inferior turbinoplasty, cryotherapy, submucous electrosurgery, and laser turbinoplasty. Unfortunately, short-term and long-term complications such as bleeding, crusting, synechiae formation, and atrophic rhinitis are often times associated with each of the above-listed techniques, due to sacrifice of mucosa for access to the target site. In light of these potential complications, surgeons have recently begun using the surgical cutting instruments previously described, and in particular a 2-mm surgical shaving instrument, to resect or shave tissue on an inside of the inferior turbinate by puncturing the turbinate anteriorly and then moving the cutting tip in a posterior fashion while resecting the targeted tissue. By resecting the interior tissue, the turbinate heals by shrinking internally, thereby allowing for better nasal airflow.

Use of a surgical micro-resecting or -shaving instrument for treatment of enlarged or inflamed inferior turbinate in the sinus cavity appears quite promising. In fact, a micro-shaving instrument is best able to achieve a primary goal of volumetric reduction of the sub-mucosal vascular stromal tissue with preservation of the overlying respitory epithelium. Unfortunately, currently available instruments for performing inferior turbinectomies have a blunt, distal end that is not conducive to a puncturing-type action. Further, available surgical micro-shaving instruments are configured such that the surgeon must rely solely upon the cutting window to resect the tissue from the bone inside the turbinate of the sinus cavity. This is a difficult and time consuming procedure, as the tissue in question is generally “tight” against the bone.

Inferior turbinate reduction with a surgical micro-shaving instrument appears highly viable, and may eliminate the complications otherwise associated with other turbinate reduction techniques. Unfortunately, however, currently available micro-shaving instruments are not designed to satisfy the needs of the inferior turbinate site. Therefore, a need exists for an inferior turbinate surgical micro-shaving instrument.

SUMMARY OF THE INVENTION

One aspect of the present invention relates to a surgical micro-shaving instrument including an outer tubular member coaxially maintaining an inner tubular member. The outer tubular member is an elongated body defining a distal section, a proximal section and a central lumen extending from the distal section to the proximal section. The distal section forms an elevator tip and a cutting window. The cutting window is positioned proximal the elevator tip and is connected to the central lumen. The elevator tip terminates at a blade-like edge and is non-blunt. In one preferred embodiment, the elevator tip terminates in a knife edge. Regardless, the elevator tip defines a top surface extending from the elevator window. In one preferred embodiment, the top surface extends in an angular fashion, planar with a plane of the cutting window. In another preferred embodiment, the top surface includes a proximal portion and a distal portion. With this configuration, the proximal portion is planar with a plane of the cutting window. Further, the distal portion extends upwardly in an angular fashion from the proximal portion, defining an obtuse angle therebetween.

During use, the surgical micro-shaving instrument is directed toward the inferior turbinate. The elevator tip is used to puncture the turbinate as well as to dissect tissue away from the turbinate bone, thereby creating improved tissue/instrument engagement.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view of a surgical micro-shaving instrument in accordance with the present invention;

FIG. 2 is a side, exploded view of the instrument of FIG. 1;

FIG. 3A is an enlarged, perspective view of an elevator tip portion of the instrument of FIG. 1;

FIG. 3B is an enlarged, cross-sectional view of FIG. 3A;

FIG. 4A is an enlarged, perspective view of an alternative embodiment elevator tip in accordance with the present invention;

FIG. 4B is an enlarged, cross-sectional view of FIG. 4A;

FIG. 5A is an enlarged, perspective view of another alternative embodiment elevator tip in accordance with the present invention;

FIG. 5B is an enlarged, cross-sectional view of FIG. 5A;

FIG. 6A is an enlarged, perspective view of another alternative embodiment elevator tip in accordance with the present invention; and

FIG. 6B is an enlarged, cross-sectional view of FIG. <b>6</b>A.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

One preferred embodiment of a surgical micro-shaving instrument or blade <b>10</b> is illustrated in FIG. <b>1</b>. The micro-shaving instrument <b>10</b> includes an outer blade assembly <b>12</b> and an inner blade assembly <b>14</b>. The outer blade assembly <b>12</b> includes an outer hub <b>16</b> and an outer tubular member <b>18</b>, whereas the inner blade assembly <b>14</b> includes an inner hub <b>20</b> and an inner elongate member <b>22</b> (illustrated in FIG. <b>2</b>). Similar to other available micro-shaving instruments, the inner elongate member <b>22</b> is sized to be coaxially received within the outer tubular member <b>18</b>. However, as described in greater detail below, the micro-shaving instrument <b>10</b> is specifically configured to optimally perform an inferior turbinate reduction procedure.

As is known in the art, the outer tubular member <b>18</b> extends distally from the outer hub <b>16</b>. To this end, the outer hub <b>16</b> can assume a wide variety of forms known in the art and may, for example, form an irrigation port <b>24</b>. Alternatively, in an alternative embodiment, the micro-shaving instrument <b>10</b> can be configured to operate without the outer hub <b>16</b>.

With additional reference to FIG. 2, the outer tubular member <b>18</b> is an elongated, tubular body defining a proximal section <b>30</b>, an intermediate section <b>32</b>, a distal section <b>34</b>, and a central lumen <b>36</b>. The outer tubular member <b>18</b> is formed from a relatively rigid, surgically safe material, preferably <b>304</b> stainless steel. The central lumen <b>36</b> extends from the distal section <b>34</b> to the proximal section <b>30</b>. In this regard, and as described in greater detail below, the distal section <b>34</b> forms a cutting window <b>38</b> (shown generally in FIG. 2) in fluid communication with the central lumen <b>36</b>. Similarly, the proximal section <b>30</b> forms an irrigation inlet <b>40</b> in fluid communication with the central lumen <b>36</b>. Upon final assembly, the irrigation inlet <b>40</b> is aligned with the irrigation port <b>24</b> otherwise formed by the outer hub <b>16</b> such that fluids can be irrigated to the cutting window <b>38</b> via the central lumen <b>36</b>.

The proximal section <b>30</b> has been depicted in FIG. 2 as having a slightly enlarged diameter to facilitate assembly to the outer hub <b>16</b>. The remainder of the outer tubular member <b>18</b>, however, is preferably sized for an inferior turbinate reduction procedure. In particular, the intermediate section <b>32</b>, as well as a majority of the distal section <b>34</b> immediately proximal the cutting window <b>38</b>, has, in one preferred embodiment, an outer diameter of 2 mm. Alternatively, the intermediate section <b>32</b>, as well as a majority of the distal section <b>34</b> immediately proximal the cutting window <b>38</b>, can have an outer diameter of 2.9 mm.

One preferred embodiment of the distal section <b>34</b> is shown in greater detail in FIGS. 3A and 3B. As previously described, the distal section <b>34</b> forms the cutting window <b>38</b>, otherwise in fluid communication with the central lumen <b>36</b>. The cutting window <b>38</b> is defined by a cutting window wall <b>39</b>. In addition, the distal section <b>34</b> forms an elevator tip <b>42</b> extending distally from the cutting window <b>38</b>. The elevator tip <b>42</b> includes opposing top and bottom surfaces <b>44</b>, <b>46</b>, as best shown in FIG. <b>3</b>B. The surfaces <b>44</b>, <b>46</b> taper in width distally, and terminate at an end <b>48</b> that is preferably relatively sharp or blade-like. Thus, the end <b>48</b> serves as a blade able to easily puncture tissue upon contact therewith. As a point of reference, in one preferred embodiment, the blade end <b>48</b> has a thickness of 0.005 inch. Unlike currently available micro-shaving instruments, the elevator tip <b>42</b>, and in particular the blade-like end <b>48</b>, is non-blunt.

To facilitate enhanced tissue interaction at the cutting window <b>38</b>, the distal section <b>34</b> preferably forms a recessed portion <b>50</b> about a majority of the cutting window <b>38</b>. More particularly, and as best shown in FIG. 3B, the cutting window wall <b>39</b> is preferably formed and orientated such that the cutting window <b>38</b> extends distally in an angular fashion, whereby the distal section <b>34</b> tapers in height (relative to the horizontal orientation of FIG. <b>3</b>B). This angular taper of the cutting window wall <b>39</b>, and thus the cutting window <b>38</b>, is represented by the angle θ in FIG. 3B, whereby θ is preferably in the range of approximately 10-16°, more preferably 13°. The recessed portion <b>50</b> is defined about the cutting window wall <b>39</b> such that the wall <b>39</b> effectively projects outwardly relative to the recessed portion <b>50</b>. This outward projection provides a distinct surface with sharp edges for engaging and/or dissecting tissue.

The recessed portion <b>50</b> is preferably concave in shape distal the cutting window <b>38</b>, as best illustrated in FIG. <b>3</b>B. With this in mind, the top surface <b>44</b> preferably extends in a linear fashion from the recessed portion <b>50</b>, tapering in height relative to the bottom surface <b>46</b>. More particularly, a plane of the top surface <b>44</b> is preferably aligned with the plane defined by the cutting window wall <b>39</b>. Thus, relative to horizontal, the top surface <b>44</b> defines an angle corresponding with the angle θ. Finally, the bottom surface <b>46</b> preferably curves to the end <b>48</b>.

The above-described construction of the distal section <b>34</b>, and in particular the elevator tip <b>42</b>, is but one acceptable configuration. For example, an alternative distal section <b>60</b> is shown in FIGS. 4A and 4B.

Once again, the distal section <b>60</b> forms a cutting window <b>62</b> and an elevator tip <b>64</b> distal the cutting window <b>62</b>. The cutting window <b>62</b> is defined by a cutting window wall <b>63</b>. A recessed portion <b>65</b> is formed about a majority of the wall <b>63</b>. The elevator tip <b>64</b> includes a proximal region <b>66</b> and a distal region <b>68</b>, with the proximal region <b>66</b> extending from the recessed portion <b>65</b>. The recessed portion <b>65</b> is formed about, and extends below, a majority of the cutting window wall <b>63</b>, with the cutting window wall <b>63</b> tapering distally as with the embodiment of FIG. <b>3</b>A. The recessed portion <b>65</b>, in combination with the tapered extension of the cutting window <b>62</b>, provides for enhanced exposure of a cutting tip (not shown) otherwise disposed within the central lumen <b>36</b> upon final assembly. Further, projection of the wall <b>63</b> above the recessed portion <b>65</b> provides a distinct surface with relatively sharp edges conducive for tissue engagement.

The proximal region <b>66</b> of the elevator tip <b>64</b> is relatively uniform in width, defined generally by a top surface <b>70</b> and a bottom surface <b>72</b>. The top surface <b>70</b> extends from the recessed portion <b>65</b> that is otherwise concave distal the cutting window <b>62</b>. As shown in FIG. 4B, the top surface <b>70</b> extends in an angular fashion from the recessed portion <b>65</b>, tapering in height relative to the bottom surface <b>72</b>. The angular orientation of the top surface corresponds with the angular taper defined by the cutting window wall <b>63</b>. Thus, the top surface <b>70</b> is generally aligned, or planar, with a plane defined by the cutting window wall <b>63</b>.

The distal region <b>68</b> extends from the proximal region <b>66</b> and terminates in a blade end <b>80</b>. As best shown in FIG. 4A, the distal region <b>68</b> tapers in width, such that the blade end <b>80</b> is a relatively sharp tip capable of piercing or puncturing bodily tissue with minimal applied force. As with the proximal region <b>66</b>, the distal region <b>68</b> includes a top surface <b>82</b> and a bottom surface <b>84</b>. As best shown in FIG. 4B, the top surface <b>82</b> of the distal region <b>68</b> extends in an angular fashion, upwardly from the top surface <b>70</b> of the proximal region <b>66</b>. In a preferred embodiment, the top surface <b>82</b> of the distal region <b>68</b> and the top surface <b>70</b> of the proximal region <b>66</b> form an obtuse angle in the range of approximately 130°-160°, more preferably 147°. The bottom surface <b>84</b> of the distal region <b>68</b> extends from the bottom surface <b>72</b> of the proximal region <b>66</b> in a curved or arcuate fashion to the blade end <b>80</b>. With this configuration, the elevator tip <b>64</b>, and in particular the distal region <b>68</b>, is optimally shaped to promote deployment of the surgical micro-shaving instrument <b>10</b> (FIG. 1) at the inferior turbinate (not shown), as well as to resect tissue. Further, the curved bottom surface <b>84</b> of the distal region <b>68</b> facilitates reciprocating movement of the distal section <b>60</b> within the inferior turbinate during a resecting or shaving procedure.

Yet another alternative embodiment distal section <b>90</b> is shown in FIGS. 5A and 5B. The distal section <b>90</b> forms a cutting window <b>92</b> and an elevator tip <b>94</b> distal the cutting window <b>92</b>. The cutting window <b>92</b> is defined by a cutting window wall <b>96</b>. A recessed portion <b>98</b> is formed about a majority of the wall <b>96</b>, as best illustrated in FIG. SA. Unlike the distal sections <b>34</b>, <b>60</b>, previously described, the recessed portion <b>98</b> extends only slightly distal the cutting window wall <b>96</b>. In other words, the distal section <b>90</b> transitions from the cutting window <b>92</b> to the elevator tip <b>94</b> immediately distal the cutting window <b>92</b>. In this regard, the elevator tip <b>94</b> is defined by a top surface <b>100</b> and a bottom surface <b>102</b>. The top surface <b>100</b> is preferably concave, extending downwardly from the cutting window wall <b>96</b>. In effect, the downward extension of the top surface <b>100</b> corresponds with the recessed portions <b>50</b> (FIG. <b>3</b>A), <b>65</b> (FIG. 4A) previously described. The concave nature of the top surface <b>100</b>, in combination with the distal taper of the cutting window <b>92</b>, provides for enhanced exposure of a cutting tip (not shown) otherwise disposed within the central lumen <b>36</b> upon final assembly.

The elevator tip <b>94</b> provides additional preferred features. First, the elevator tip <b>94</b> terminates in a blade end <b>104</b>. As best shown in FIG. 5A, the elevator tip <b>94</b> tapers distally in width, such that the blade end <b>104</b> is a relatively sharp tip capable of piercing or puncturing bodily tissue with minimal applied force. Further, the bottom surface <b>102</b> is preferably curved so as to facilitate reciprocating movement of the distal section <b>90</b> within the inferior turbinate (not shown) during a resecting or shaving procedure. Also, the top surface <b>100</b> is defined by opposing edges <b>106</b>. As best shown in FIG. 5B, one or more serrations <b>108</b> are formed in the edges <b>106</b>. These serrations <b>108</b> are configured to readily resect or shave contacted tissue.

Yet another alterative embodiment distal section <b>120</b> is shown in FIGS. 6A and 6B. The distal section <b>120</b> forms a cutting window <b>122</b> and an elevator tip <b>124</b> distal the cutting window <b>122</b>. The cutting window <b>122</b> is defined by a cutting window wall <b>126</b>. A recessed portion <b>128</b> is formed about a majority of the wall <b>126</b>, as best illustrated in FIGS. <b>6</b>A. Similar to the distal section <b>90</b> (FIG. <b>5</b>A and <b>5</b>B), the recessed portion <b>128</b> extends only slightly distal the cutting window wall <b>126</b>. In other words, the distal section <b>120</b> transitions from the cutting window <b>122</b> to the elevator tip <b>124</b> immediately distal the cutting window <b>122</b>. Also, as with previous embodiments, the cutting window wall <b>126</b> tapers distally relative to a central axis of the distal section <b>120</b>.

The elevator tip <b>124</b> includes a top surface <b>130</b> and a bottom surface <b>132</b> extending along a first section <b>134</b> and a second section <b>136</b>. The elevator tip <b>124</b> terminates in a blade end <b>138</b>. As best shown in FIG. 6A, the elevator tip <b>124</b> tapers distally in width, such that the blade end <b>138</b> is a relatively sharp tip capable of piercing or puncturing bodily tissue with minimal applied force.

With respect to the first section <b>134</b> of the elevator tip <b>124</b>, the top surface <b>130</b> is preferably concave, forming a depression relative to a distal end of the cutting window wall <b>126</b>. For example, in one preferred embodiment, the top surface <b>130</b> at the first section <b>134</b> defines, in longitudinal cross-section, a concave curve having a radius of approximately 0.06 inch, although other dimensions are acceptable. Regardless, this preferred attribute provides for enhanced exposure of a cutting tip (not shown) otherwise disposed within the central lumen <b>36</b> upon final assembly.

The bottom surface <b>132</b> is curved along the first and second sections <b>134</b>, <b>136</b>. However, unlike previous embodiments, the bottom surface <b>132</b> forms a concave curve in longitudinal cross-section (as shown in FIG. 6B) as the bottom surface <b>132</b> transitions from the first section <b>134</b> to the second section <b>136</b>. This one preferred configuration promotes advancement of the elevator tip <b>124</b> posteriorly through the inferior turbinate (not shown). In one preferred embodiment, a curve of the bottom surface <b>132</b> is such that, relative to the cross-sectional view of FIG. 6B, the bottom surface <b>132</b> elevates from the first section to the blade end <b>138</b> a preferred distance (or height) in the range of 0.056-0.06 inch, most preferably 0.058 inch. Alternatively, other dimensions can be employed.

Regardless of exact form, in one preferred embodiment, the distal section <b>34</b> (FIG. <b>3</b>A), <b>60</b> (FIG. <b>4</b>A), <b>90</b> (FIG. <b>5</b>A), or <b>120</b> (FIG. 6A) is formed separate from a remainder of the outer tubular member <b>18</b> (FIG. <b>2</b>), and subsequently assembled thereto. With this fabrication technique, the distal section <b>34</b>, <b>60</b>, <b>90</b>, <b>120</b> can be formed from a material more amenable to precise manufacturing tolerances. For example, in one preferred embodiment, the distal section <b>34</b>, <b>60</b>, <b>90</b>, <b>120</b> is formed from heat treated, 17-4 stainless steel, whereas a remainder of outer tubular member <b>18</b> is a 304 stainless steel material. Regardless, the so-formed distal section <b>34</b>, <b>60</b>, <b>90</b>, <b>120</b> is secured to the intermediate section <b>32</b> of the outer tubular member <b>18</b>, such as by a laser weld.

Returning to FIG. 2, the inner blade assembly <b>14</b> is of a type commonly known in the art, whereby the inner tubular member <b>22</b> extends from the inner hub <b>20</b>. In one preferred embodiment, the inner hub <b>20</b> is configured for selective attachment to a handpiece (not shown) that can be operated to automatically maneuver the inner blade assembly <b>14</b> during use.

The inner tubular member <b>22</b> forms a cutting tip <b>150</b> at a distal end thereof. Upon final assembly, and with respect to the one embodiment of in FIG. 1, the inner tubular member <b>22</b> is coaxially disposed within the outer tubular member <b>18</b> such that the cutting tip <b>150</b> is exposed through the cutting window <b>38</b>. The cutting tip <b>150</b> can assume a wide variety of forms, and preferably forms a series of teeth or cutting edges designed to engage and resect (or shave) tissue.

As previously described, the surgical micro-shaving instrument <b>10</b> of the present invention is particularly useful for an inferior turbinate reduction procedure. In one preferred embodiment, the assembled instrument <b>10</b> is deployed to the sinus cavity, with the blade end <b>48</b> (FIG. <b>3</b>A), <b>80</b> (FIG. <b>4</b>A), <b>104</b> (FIG. <b>5</b>A), or <b>138</b> (FIG. 6A) being inserted into the anterior face of the inferior turbinate just medial to the muco-cutaneous junction. The blade end <b>48</b>, <b>80</b>, <b>104</b>, or <b>138</b> is then firmly pushed towards the turbinate bone, piercing through the turbinate mucosa. In this regard, because the blade end <b>48</b>, <b>80</b>, <b>104</b>, <b>138</b> is relatively sharp, the tissue is readily punctured, in direct contrast to blunt-ended instruments currently available. The distal section <b>34</b> (FIG. <b>3</b>A), <b>60</b> (FIG. <b>4</b>A), <b>90</b> (FIG. <b>5</b>A), <b>120</b> (FIG. 6A) is then moved in a posterior fashion to resect submucous of the inferior turbinate. In one preferred embodiment, a sub-mucosal pocket is dissected by tunneling the distal section <b>34</b>, <b>60</b>, <b>90</b>, <b>120</b> in an anterior to posterior and superior to inferior sweeping motion. Once an adequate pocket has been established, tissue resection is initiated, preferably with the cutting tip <b>150</b> facing laterally and moving back and forth in a sweeping motion analogous to liposuction. Regardless, both the cutting tip <b>150</b> of the inner tubular member <b>22</b>, as well as the cutting window wall <b>39</b> (FIG. <b>3</b>A), <b>63</b> (FIG. <b>4</b>A), <b>96</b> (FIG. <b>5</b>A), or <b>122</b> (FIG. 6A) that otherwise projects relative to a remainder of the elevator tip <b>42</b> (FIG. <b>3</b>A), <b>64</b> (FIG. <b>4</b>A), or <b>94</b> (FIG. <b>5</b>A), or <b>124</b> (FIG. <b>6</b>A), respectively, assist in engaging and resecting contacted tissue. Further, with the embodiment of FIGS. 5A and 5B the serrations <b>108</b> formed by the edges <b>106</b> further assist in engaging and resecting contacted tissue. In effect, the elevator tip <b>42</b>, <b>64</b>, <b>94</b>, <b>124</b> dissects tissue away from the bone inside of the turbinate, so that the cutting tip <b>150</b> of the inner tubular member <b>22</b> can more easily contact, and therefore resect or shave, desired tissue. The handpiece (not shown) is operated to cause the cutting tip <b>150</b> to rapidly resect or shave the contacted tissue, with the removed tissue being suctioned away from the target site.

The surgical micro-shaving instrument of the present invention provides a marked improvement over previous designs. With respect to inferior turbinate reduction procedures, use of a micro-shaving tool provides a distinct advantage over other available techniques (such as cryosurgery, electrocautery, laser, etc.) as the tool does not destroy mucousa in order to access the submucous tissue to be resected. In addition, as compared to available 2 mm and 2.9 mm micro-shaving tools, the elevator tip associated with the present invention readily pierces the inferior turbinate, as well as dissecting targeted tissue away from the turbinate bone, thereby promoting more efficient and effective cutting.

Although the present invention has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes can be made in form and detail without departing from the spirit and scope of the present invention.